In recent years, a head up display apparatus for vehicle which projects a display image onto a windshield of a vehicle to image a virtual image in front of a driver and which is configured to be capable of visually recognizing the display image without lowering driver's eyes, even during driving, is implemented (for example, see JP2013-32087A).
The head-up display apparatus for a vehicle disclosed in JP2013-32087A, for example, includes a recess surface-shaped dustproof cover provided to reflect outer light (sun light or street light) entered an inside from an outside of the windshield toward a position invisible to the driver.
However, in such a head-up display apparatus for a vehicle, the dustproof cover is configured by a recessed surface having a fixed curvature, for example. A size of the dustproof cover in an inside direction (depth direction) of an instrument panel therefore becomes large. In addition, a space of an inside of the instrument panel (inside of the vehicle) necessary to contain the head-up display apparatus for a vehicle increases toward a depth side of the vehicle as a size in the depth direction of the dustproof cover increases. As a result, there is a problem that a large installation space is necessary for the inside of the vehicle.
This problem notably appears, in particular, in a head-up display apparatus for vehicle that displays a virtual image of a large size at a position of a large imaging distance (remoteness). In other words, in a head-up display apparatus for a vehicle executing a large screen-remote imaging, a passing area of a light flux passing through an upper surface of the instrument panel toward the windshield becomes large in order to accomplish the remoted imaging distance by increasing a magnification ratio of the display image. It is, therefore, necessary to increase a size of an opening provided in the upper surface of the instrument not to shield the passing area.
Accordingly, since the size of the dustproof cover provided to close the wide opening in this way also increases, a size of the dustproof cover in the depth direction becomes large and a wide installation space must be secured in the inside of the vehicle.